Process for preparing motor fuel



Patented Aug. 13, 1935 UNITED STATES PATENT OFFICE PROCESS FOR PREPARING MOTOR FUEL No Drawing. Application February 6, 1934,

Serial No. 709,948. ary 11, 1933 30lalms.

This invention relates to a process for preparing a liquid fuel for combustion engines with fuel injection at the end of the compression stroke.

In the case of combustioirengines of the Diesel and semi-Diesel type and especially in the case of high-speed engines of the type aforementioned, a relatively long period of time often elapses between the injection and the ignition of the fuel.

It has already been proposed to remedy this defect by adding to the fuel an ignition agent having the property of exploding at a temperature below the ignition temperature of the fuel.

Thus, it has been proposed to add to Diesel fuel products of decomposition of percarbonates, perborates, and persulfates, or such compounds as benzoyl peroxide, etc.

These substances, however, have many drawbacks: They are dangerous to handle, they are unstable and decompose rapidly at ordinary temperatures, necessitating the use of various stabilizing agents, such as organic amido-derivatives, and, finally, they do not dissolve to a sufficient degree in the fuel to be improved. This necessitates either the use of additional agents to dissolve the peroxide, or of elaborate methods to disperse it in the fuel.

According to this invention, there are added to the fuel small quantities of tetraline peroxide which is an organic peroxide soluble in the fuel. This addition is effected either in pure form, or in the form of a solution containing said peroxide. Tetraline peroxide can be added to various oils to be used as Diesel fuel, such as gas oil, heavy pressure distillate, Edeleanu extract of kerosene, coal tar fractions, etc. The preparation of tetraline peroxide has been described in the Helvetica Chimica Acta", 1932, p. 1390, by Hartmann and Seiberth, and in the Berichte cler Deutschen Chemischen Gesellschaft, 1933, p. 61, by Hock and Susemihl. It is a highly suitable, easily made, and a substantially stable product, which dissolves to a sufficient degree in the motor fuel. This makes it unnecessary to use an additional agent to dissolve the peroxide, the difficulty of dispersing it in the fuel being likewise avoided.

Alternatively tetraline peroxide may be caused to form in the fuel itself, in which case its forma- In the Netherlands Febrution may be controlled and accelerated by the use of suitable catalysts.

In general, the desired object will be fully attained by adding to 1 /2% of a peroxide to the motor fuel. Therefore, the peroxide used has to be, as a rule, at least for to 1 soluble in the fuel, if it is to have its favorable effect.

In the case of some peroxides, however, such as, for example, the benzoyl peroxide, these percentages cannot be realized due to their low solubility in hydrocarbon oil. In the case of tetraline peroxide, quantities as high as 4 or 5% may be dissolved in fuel oils. Such high percentages may, however, be added only by way of exception, a very favorable effect being usually produced, as stated, by the addition of to 1 of tetraline peroxide.

This is illustrated by the following examples, wherein the imrovement of the gas oil used is expressed by the increase of the so-called cetene number. For the significance of this figure reference is made to an article of G. D. Boerlage and J. J. Broeze Ignition quality of Diesel fuels as expressed in cetene numbers, published in the July, 1932, number of the S. A. E. Journal.

Example I .--A gas oil with an original cetene number of 42 was treated by the addition of 70, 1%, 1 of tetraline peroxide. The cetene number rose to 50, 56 and 60 respectively, whereby a moderately suitable fuel for high speed Diesel engines was changed into a highly suitable fuel.

Example II.An Edeleanu extract of kerosene with an original cetene number of 14 was treated with 5% of tetraline peroxide. The cetene number was thereby raised to 33, and the product, which could not before treatment be used for fuel in pure form, became quite suitable for stationary engines.

I claim as my invention:

1. A liquid fuel for combustion engines with fuel injection at the end of the compression stroke containing small quantities of tetraline peroxide added thereto.

2. The fuel of claim 1 containing not more than 5% of tetraline peroxide added thereto.

3. The fuel of claim 1 containing from to 1 of tetraline peroxide added thereto.

FRANZ RUDOLF MOSER. 

